VVapi provides an infrastructure platform for building enterprise-grade voice AI agents. It offers flexible APIs and an SDK that enable developers to create, test, and deploy voice agents capable of handling inbound and outbound calls. The platform stitches together speech-to-text, large language models, and text-to-speech from integrated or third-party providers, with sub-500ms response times, and users can bring their own API keys or use Vapi’s models. Vapi differentiates itself with a developer-centric approach, provider-agnostic orchestration, and scalable, low-latency voice operations aimed at use cases like customer support and appointment scheduling, across industries from healthcare to finance. The goal is to simplify building and scaling AI-powered voice agents for businesses.
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Company Size
51-200
Company Stage
Series B
Total Funding
$70.1M
Headquarters
San Francisco, CA
Founded
2021
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Fleet Week with Vapi - recap. Vapi Editorial Team - Oct 20, 2026 On October 8, over 30 voice AI builders joined the Vapi team on a chartered yacht in San Francisco Bay to connect and watch the Blue Angels practice for Fleet Week. Its goal was simple: voice AI builders get invited to plenty of standard networking events and rarely go. A regular office workshop has to compete with so much noise. Watching jets from a boat on the Bay, however, who could say no? The agenda featured fireside chats and talks hosted by Deepgram, Kouper Health, and Coval, followed by a hands-on technical workshop. Hot topic: speech-to-speech & GPT Live. GPT Live was easily one of the most discussed topics on board. Vapi spoke with a principal engineer at a major consumer marketplace who already deployed a live agent with it, an enterprise PM comparing it to their custom pipeline, and several others evaluating costs and ROI. Key takeaway: skipping traditional transcription/synthesis cuts latency and creates super fluid turns, but you trade off granular control over key terms and scripting. Most teams are still figuring out which specific use cases benefit most from speech-to-speech vs classic pipelines. Focusing on user experience & natural flow. The question is no longer "Can voice AI converse?" - the focus has completely shifted to "How do we make it feel natural?" Top UX themes discussed included: backchanneling (listening noises like "mhm" or "got it" to prevent dead air), perceived vs measured latency (an 800ms pause feels long unless filled naturally), and measuring naturalness (quantifying conversational quality beyond simple latency metrics). Vapi also saw huge interest in embedding voice natively inside web/mobile apps (like CRMs) rather than treating it as a standalone phone channel. Even everyday use cases like appointment scheduling carry hidden complexity when callers change their mind mid-sentence. Enterprise trends: platform vs. In-House. Many enterprise teams present had already built internal voice stacks. These led to incredible conversations, as teams with custom builds know exactly where maintenance overhead gets heavy and where things break. Why choose a platform over direct model APIs? It comes down to reliability and future-proofing. Managing multi-provider failover and staying updated across STT, LLM, and TTS models is a massive maintenance headache to own long-term. Pro Tip for Sales & GTM Teams: The most immediate entry point isn't always greenfield innovation; it's active contact center migrations with existing budgets and a strong appetite for modernization. Key takeaways & what's next. The boat format worked remarkably well. Spending four hours together in a shared space sparked organic discussions on topics like interruption handling that rarely happen at standard conferences. A big thank you to its co-hosts Deepgram and Coval, as well as everyone who joined Vapi. Most boat attendees will be joining Vapi at VapiCon 2026 as well, taking place Nov 11-12 at Fort Mason. See the full agenda and get tickets here!
Meet Jeff Liu, Vapi's new VP of Engineering. Team Vapi - Oct 20, 2026 Vapi is excited to welcome Jeff Liu as its VP of Engineering. Jeff has spent the better part of two decades building platform infrastructure and supporting the teams that run it. He joins at a moment when the team is shipping new products and customers are running voice in production at scale. Jeff joined the team because he believes voice is the next wave of AI adoption, and because Vapi is building the platform that voice deployments run on rather than a single application on top of one. Vapi sat down with him to talk about the path here, what he's prioritizing first, and why he's convinced voice is the future. Tell Vapi a bit about yourself and your career path leading up to Vapi. I came to Vapi from Turing, where I was VP of Engineering, leading platform and infrastructure engineering for about five years. Before that I spent a year at LinkedIn as a senior engineering leader leading flagship product engineering, and before LinkedIn, six years at Google. That's where I first moved into management, as a tech lead manager. Earlier in my career, I was at Twitter and Splunk when both were still startups, and before that at a startup called Everdream that was acquired by Dell. So for almost two decades, I have mostly been building platforms and infrastructure at a scale, the work I grew up on and the work that carried me from engineer into leadership. I built my career one step at a time, and I think that matters. I've done the jobs my team does now, and I've built systems that are scaled to support very large user bases. What made Vapi stand out when you were deciding on your next move? I'm passionate about voice AI, and I'll say that plainly because it drove the decision. The models have reached a level where they can support voice, and I believe the next big wave of AI adoption will be built on that. You can already see it in the market. For the last couple of years, the strongest stories about AI actually landing inside a business have come from voice, and customer experience is the clearest example. When I talked with the Vapi leadership team about where the company is going, that conviction matched what I was already seeing. Vapi is growing fast and sits at the frontier of where voice technology is headed. Other offers I saw focused on building a solution for one specific market, and I cared more about building a platform that supports a wide range of use cases. You've spent years at Google and LinkedIn. What excites you about a company at this stage? I started at startups, Everdream, then Splunk, then Twitter, all early in their life. I learned a lot from those years about how startups actually work and what they can do for a career that a big company can't. After my time at Google and LinkedIn, I always knew I wanted to come back to that. Vapi was the right answer. At this stage you can see your own fingerprints on the product and the platform, and I have a real chance to shape its strategy. The decisions you make this quarter decide what the company looks like in two years. That's a lot harder to find once a company is large, and it's the part I missed. You've described Vapi as a platform; why does that framing matter to you? The thing I took away from talking with the founders is that Vapi isn't building one application. It's building a platform that companies can build their businesses on. I see it as what AWS did for cloud computing, applied to voice. That's the kind of work I've done for most of my career, and the kind I've seen succeed at scale. Platform and infrastructure is how I grew from engineer to leader, and I've learned a lot over the years about what it takes to run one. I can bring those learnings to the next phase of this company. The technical fit and the market Vapi is going after lined up, and that's what attracted me most. What are your first priorities in coming into this role? Number one is platform reliability and scalability. I view it as the most important part of running a platform, and Vapi has to keep investing in it so Vapi can support what's coming: ongoing product improvements and some high-impact launches in the next few quarters. Its first job is to build a platform reliable enough to carry its products. The job is to keep operating like a platform: reliability as the foundation, with investments in efficiency and products so customers can get more done on Vapi with better quality at a lower cost. A platform earns its place when builders deliver more business value on it for less money than they'd spend anywhere else. That's what Vapi has built, and what Vapi'll keep building. What do you do outside of work that keeps you grounded? Most of my time outside work goes to my kids and my family. The other thing is music. I wanted to learn an instrument for a long time and never had the chance until the pandemic, when I finally started on piano, then guitar. It took me a long while to get through my first song. I kept at it for a couple of years, picked up a few more, and the piano ended up making guitar much easier to learn afterward. What I enjoy most isn't just the playing, it's the music theory. How chords and melody fit together to build a song, and how you have to design that on purpose. I see a lot of parallels between music and my work as an engineer. The melody carries the idea, and the chords are the platform you build underneath it so the idea can land. That comparison probably says something about how I think about work too.
Have your personal assistant make the call you keep putting off. Vapi Editorial Team - Sep 30, 2026 General information is more accessible than ever. If the answer is online, an agent can find it and send it to you in minutes. The specific, personal things still need a phone call. Whether the store on Main Street has the shoes you love in your size. Whether there's an appointment that fits your short window Tuesday morning or Wednesday afternoon. Whether a seat upgrade is possible on your cross-country flight. Each one starts with a real conversation with a real person about what you want. So those calls get put off, because getting that help isn't easy. You sit on hold, work through a phone menu, or wait for a callback that never comes. Today Vapi is launching Vapi Personal Agent Calling in beta, giving your personal assistants a phone. You tell it what you need; it dials, holds the conversation, and reports back. It works with the most popular personal assistants, including Muse, Instinct, GrokBot, ChatGPT Work, Claude Code, OpenClaw, and Hermes. Vapi Personal Agent Calling is the voice layer beneath your agent. You give your assistant the task and the details that matter: the business, the dates that work, an order number if there is one. Vapi handles the call itself so the assistant can talk to a person on the other end and come back with a result. It's simple; just copy this prompt into your assistant and fill in the brackets: "Open phone.vapi.ai, read the agent instructions, and call [business + location] to [task]." Here's what it looks like in the world. While testing this feature, its Head of Revenue, Bryan Parman, asked his assistant to use phone.vapi.ai to call an airline and get his seat upgraded for additional legroom. Bryan is tall enough that a standard economy seat is less than ideal for his knees. He typed the request in plain text, approved the call, and went back to work. He asked his agent to call the airline and move him to Economy Plus in an aisle seat, only if there was no charge, and not to change or cancel the flight if that isn't possible. The agent dialed the airline, worked through the automated phone menu, and waited for a person. It sat on hold for 14 minutes while Bryan was working through the end of the quarter. He got a text when the call connected, another when the agent reached a human, and kept working through all of it. When it got through, the agent introduced itself as Bryan's assistant, explained the request, and asked for the upgrade. The rep said only one aisle seat was left and quoted $51.69. Per Bryan's instructions, the agent declined to pay, so the rep waived the fee. A final text landed on Bryan's phone along with an email conversation: Economy Plus, aisle, no charge. Five extra inches of legroom, and zero minutes of hold music. A personal assistant can already search, draft, and fill out forms. But the tasks shaped by your preferences, your size, your schedule, your seat, get done by asking a person, and asking a person means picking up the phone. You sit on hold for 30 minutes to ask about a flight upgrade that may not be granted. You call the store and get transferred to the back. You make the call you've been dreading, or you don't, and the shoes sell out. These calls cost an afternoon or are just unpleasant, so they land on the back burner. phone.vapi.ai gives your assistant a phone, so those calls stop waiting on you. How to use it. * Open your assistant. Claude, Cursor, Muse, OpenClaw, Hermes, Instinct or Grokpot. * Paste this and fill in the brackets: "Open phone.vapi.ai, read the agent instructions, and call [business + location] to [task]." * Approve once. Your browser opens a login page for your Vapi account. Sign in, close it. The assistant connects, makes the call, and sends you the result. Why Vapi. Vapi built the voice infrastructure that enterprises use to run calls at scale: the orchestration across speech-to-text, the model, and text-to-speech, plus the telephony underneath. That's the same stack your assistant is using when it dials the dentist, and the stack top organizations are using to power production-grade voice deployments. With Vapi there are no API keys, or confusing connectors. Authenticate with your Vapi account, and then provide one sentence of context to your assistant and it's on the phone making calls on your behalf. Personal assistants are getting good at knowing what you need. Vapi is the voice layer below all of them, so they can finally pick up the phone. There is no added cost on top of your Vapi minutes. Try it at phone.vapi.ai, and tell Vapi who your assistant called.
AI voice agent platform: how to choose the right one in 2026. Persistence Team · August 26, 2026 On this page Key takeaways * There is no single best AI voice agent platform. Independent tests from Ventureharbour and Arahi both put Vapi, Retell AI, and Bland AI in their top tier for latency and reliability (ventureharbour.com, arahi.ai). * Retell AI shows up first in nearly every 2026 ranking, including Vellum's guide and its own blog, but vendor-published lists should be read as one data point, not the final word (vellum.ai, retellai.com). * Cost is usually billed per minute of call time, and per-minute cost is exactly what Ventureharbour's hands-on test set out to measure across 7 platforms (ventureharbour.com). * For raw voice quality, ElevenLabs' models are the ones most platforms license or benchmark against, since ElevenLabs sells voice agents built on its own speech models (elevenlabs.io). * Developer-first platforms like Vapi let you plug in different LLMs and voice models rather than locking you to one stack (vapi.ai). What an AI voice agent platform actually does. An AI voice agent platform is the infrastructure layer that turns a phone call into a conversation with software. It handles speech-to-text, a language model that decides what to say, text-to-speech, and the telephony that connects it all to a real phone number. Vapi describes itself this way directly: a platform for developers building and deploying voice AI agents (vapi.ai). Bland AI positions itself similarly for enterprises, emphasizing self-hosted models and sub-second latency (bland.ai). No-code options like OmniDimension aim at businesses that want a voice agent without writing code, covering calls, lead capture, and 24/7 coverage (omnidim.io). The honest answer is that it depends on what you're testing for, and the rankings shift depending on who wrote them. Ventureharbour built voice agents on 7 tools - including Vapi, Retell, Synthflow, and Bland - and tested them hands-on for latency and cost-per-minute rather than relying on marketing claims (ventureharbour.com). Arahi ran a similar test across 11 platforms, ranking Vapi, Retell, Bland, Synthflow, and ElevenLabs on latency, voice quality, and telephony (arahi.ai). Vellum's 2026 guide ranks Retell AI first, followed by SquadStack, Leaping AI, PolyAI, Bland AI, Voiceflow, and Sierra AI (vellum.ai). Retell AI's own blog also puts itself first, ahead of PolyAI, Cognigy, CloudTalk, Lindy AI, and Synthflow - useful for seeing how it stacks itself against competitors, but worth reading with that context in mind (retellai.com). The pattern across independent tests: Vapi, Retell AI, and Bland AI consistently place near the top. The top 3 AI voice agent platforms, by how often they rank well. Across both vendor lists and independent hands-on tests, three names repeat: Retell AI, Vapi, and Bland AI. Retell AI appears first in Vellum's independent guide and in its own comparison (vellum.ai, retellai.com). Vapi is built specifically for developers who want to build voice agents in minutes and shows up in both the Ventureharbour and Arahi hands-on tests (vapi.ai, ventureharbour.com, arahi.ai). Bland AI markets itself on enterprise compliance, self-hosted models, and sub-second latency, and also appears across all three independent comparisons (bland.ai, ventureharbour.com, arahi.ai, vellum.ai). PolyAI and Synthflow are the next most frequently cited names, particularly for customer support use cases (retellai.com, vellum.ai, arahi.ai). Most platforms bill by the minute of call time rather than a flat monthly fee, which is why Ventureharbour's comparison specifically measured cost-per-minute across the 7 platforms it tested rather than just listing subscription tiers (ventureharbour.com). That per-minute model matters more than a headline price, because your actual bill scales with call volume and average call length. If you're comparing platforms, ask for cost-per-minute at your expected call volume and length, not just the plan price, since that's the number independent testers actually rely on to compare tools apples-to-apples. This splits into two separate questions: which model generates the voice, and which model decides what to say. ElevenLabs is the name most associated with voice quality - it sells voice agents built directly on its own speech models and markets them for real-time, human-like conversations (elevenlabs.io). For the reasoning layer, developer-first platforms like Vapi are built so you can plug in different LLMs rather than being locked to one (vapi.ai). Community discussion on Reddit's r/AI_Agents reflects the same split: builders mix and match a speech model, an LLM, and a telephony layer rather than picking one all-in-one model for everything (reddit.com). A simple way to evaluate any platform. Test the same three things every independent review tested: latency (how long before the agent responds), voice quality (does it sound natural on a real phone line, not just a demo), and cost-per-minute at your expected volume. Ventureharbour and Arahi both built real agents and measured these directly instead of trusting spec sheets (ventureharbour.com, arahi.ai). Whatever platform you land on, run your own test call before committing - rankings change fast in this category, and both Ventureharbour and Arahi's guides are dated 2026, meaning even recent lists get outdated within months. For related guidance, continue with Upfirst AI Receptionist: Pricing, Features, and Whether It's Worth It and Nextiva AI Receptionist: What XBert Does and What It Costs. Related resources. Frequently asked questions. Which AI voice agent platform is best? How much do AI voice agents cost? Which AI model is best for voice agents? Try persistence. Persistence Automate your calls. Connect with Persistence.
Vapi simulations: test for every type of caller. Vapi Editorial Team - Aug 18, 2026 To help teams ship voice agents they can trust, Vapi, Inc. is launching Vapi Simulations, a native, AI-powered testing feature. Simulations puts AI testers on the other end of the call, each with a distinct personality and a scenario drawn from your real customers. They hold actual conversations with your agent, and every run comes back with clear pass/fail results, a full transcript, and a recording. With this new feature, you can feel confident in your deployment by validating an agent before it's in production, catching regressions after every change, and knowing it handles edge cases. Here's why Vapi, Inc. built it, how it works, and what it changes for you. Why Vapi, Inc. built it. Most teams find out their voice agent has a problem from production. A customer complains, or a conversion metric slips, and someone pulls call recordings to figure out what happened. By then, the issue has already cost you brand trust, revenue, and time spent tracking down specific conversational failures. For enterprises, that risk holds back scale. Nobody rolls a voice agent out to their full call volume without a systematic way to prove it works first. Until now, testing meant placing manual calls, which works for one agent and one change, and stops working the moment you have ten agents and a prompt update shipping every week. There's no easy way to spot a regression aside from calling your own agent and hoping you covered the right paths. Evals are still the right tool for controlled validation, but they run mock conversations with predefined message sequences, and a predefined script can't capture what real callers do. Real callers interrupt. They give you a date in the wrong format, change their mind halfway through, and get frustrated when the agent asks them to repeat themselves. Simulations closes that gap natively. Build, test, iterate, and monitor in one platform, with the full context of your agents behind every test, against the complexity real callers actually bring. How it works. Simulations are built from a few different configurations: Personalities define who's calling your agent. Each one is a full mock configuration, with its own model, voice, and system prompt. An "impatient customer" who interrupts long responses. A confused first-time caller who needs everything repeated. You design testers around the customer types you actually see, including the ones who might give your agent the hardest time. Scenarios define what the caller wants and how you measure success. Each scenario pairs tester instructions ("try to book an appointment for a date that isn't available") with evaluations: structured outputs extracted from the conversation and compared against expected values, so every run produces an explainable pass or fail rather than a "sounds good" vibe. Simulations and suites put them together. A simulation pairs one scenario with one personality; a suite groups related simulations so you can re-run your whole coverage after any change. Runs execute against the assistant or squad you are testing, and you watch results come in live. Two details make this work for real-world testing. Tool mocks let you simulate API responses at the scenario level, so you can test how your agent handles a calendar API error or a timeout without breaking anything real. And two testing modes let you match cost to purpose: chat mode runs conversations as text for fast, cheap iteration, while voice mode runs the full audio pipeline with recordings for end-to-end validation before you ship. For teams that want testing in their deployment pipeline, you can create runs through the API, with quality gates that block a deploy when pass rates drop. The quickstart and advanced guide cover setup step by step. What you can do with it. Validate before launch. An engineer is about to deploy a patient intake agent that should hand off to a nurse when a caller gets frustrated. She runs the frustrated-caller simulation, confirms the agent makes the transfer as intended, and ships knowing that path works. Catch regressions after changes. A PM updates a lead-qualification prompt to handle a new pricing objection. The simulation suite flags that the agent now skips the eligibility confirmation step. She adjusts the prompt, the test passes, and the change ships without a regression reaching callers. Prove your guardrails hold. A healthcare compliance team needs confidence that its support agent never references medication dosages or gives clinical advice. They run guardrail-specific simulations against those boundaries and keep the passing runs as a record of exactly what was tested. Test failure paths you can't produce on demand. An engineer wants to know how her scheduling agent behaves when the calendar API fails. She mocks an error response and discovers the agent tells the caller the appointment was booked. She fixes the error handling and re-runs to confirm before the change goes live. Get started. Simulations are live in your dashboard. Start in chat mode with a smoke test against an agent you already run, then build out the personalities your customers actually bring. The quickstart will get your first run finished in minutes. Know your agent works before your customer finds out it doesn't
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Industries
Company Size
51-200
Company Stage
Series B
Total Funding
$70.1M
Headquarters
San Francisco, CA
Founded
2021
Find jobs on Simplify and start your career today
Don't see your dream role? Check out thousands of other roles on Simplify.Browse all jobs